Hello:

When I try to use hdparm -B with a ST3500418AS disk from Seagate I get:

hdparm -B 255 /dev/sda
/dev/sda:
setting Advanced Power Management level to disabled
HDIO_DRIVE_CMD failed: Input/output error
APM_level = not supported

This disc from Seagate doesn't support hdparm -Z to disable the  automatic  power-saving  function, specific for some Seagate ST3xxxxx drives.

I get the same result, when I try to use the hdparm -B command with a WDC WD5000AADS-0 disk from Western Digital.

With the fist one, this isn't a very big problem because it need specific commands to enter into idle mode, but with the second one, with only 499 hours of working time, it shows 48.771 as Load_Cycle_Count SMART parameter.

If you cannot change the Set Advanced Power Management feature, this disk from Western Digital, parks his heads automatically every 8 seconds. At Western Digital forums I have found a procedure to change this annoying behaviour under Windows and Mac, but noting for Linux. 

Therefore, this disc doesn't need any command of energy control to parks its heads and as result the load cycle count increases automatically and very quickly. If you see its technical information, you will find that this disk can afford 300.000 load cycles without damage. With this ratio, I will have problems in 3.118 hours of working time.

Best regards.